from django.shortcuts import render
from django.http import HttpResponse, HttpResponseRedirect
from django.template import loader
from django.shortcuts import render, get_object_or_404
from django.urls import reverse
from django.views import generic
from .models import Question, Choice
from django.utils import timezone

"""老版试图方法"""
#
# # Create your views here.
# def index(request):
#     latest_question_list = Question.objects.order_by('-pub_date')[:5]
#     template = loader.get_template('polls/index.html')
#     context = {
#         'latest_question_list': latest_question_list,
#     }
#     # output = ','.join([q.question_text for q in latest_question_list])
#     # return HttpResponse(template.render(context, request))
#     return render(request, 'polls/index.html', context)  # 使用render()无需导入loader 和 HttpResponse
#
#
# def detail(request, question_id):
#     # 处理投票详情试图
#     # try:
#     #     question = Question.objects.get(pk=question_id)
#     # except Question.DoesNotExist:
#     #     raise Http404("Question does not exist")
#
#     # 也可以使用get函数
#     question = get_object_or_404(Question, pk=question_id)
#     return render(request, 'polls/detail.html', {'question': question})
#     # return HttpResponse("You're looking at question %s." % question_id)
#
#
# def results(request, question_id):
#     question = get_object_or_404(Question, pk=question_id)
#     response = "You're looking at the results of question %s."
#     return render(request, 'polls/results.html', {'question': question})
#
#
# def vote(request, question_id):
#     question = get_object_or_404(Question, pk=question_id)
#     try:
#         selected_choice = question.choice_set.get(pk=request.POST['choice'])
#     except(KeyError, Choice.DoesNotExist):
#         # Redisplay the question voting form
#         return render(request, 'polls/detail.html', {
#             'question': question,
#             'error_message': "You didn't select a choice.",
#         })
#     else:
#         selected_choice.votes += 1
#         selected_choice.save()
#         return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))


"""优化试图层"""


class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """Return the last five published questions not including those set to be published in the future"""
        return Question.objects.filter(pub_date__lte=timezone.now()).order_by('-pub_date')[:5]
        # return Question.objects.order_by('-pub_date')[:5]


class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        :return:
        """
        return Question.objects.filter(pub_date__lte=timezone.now())


class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'


def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except(KeyError, Choice.DoesNotExist):
        # Redisplay the question voting form
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': "You didn't select a choice.",
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))
